Trimmer Error when publishing on IOS

[osyyyS]

Hi, after upgrading from 1.0.0 to 2.0.0 when trying to publish for IOS with Realase mode:

 dotnet publish ${{ env.CSPROJ_TO_APP }} -c Release

I am getting this error:

Fitaino.App -> /Users/oploeger/Desktop/actions-runner/_work/Fitaino/Fitaino/apps/Fitaino.App/bin/Release/net10.0-ios/ios-arm64/Fitaino.App.dll
  Optimizing assemblies for size may change the behavior of the app. Be sure to test after publishing. See: https://aka.ms/dotnet-illink
  Optimizing assemblies for size. This process might take a while.
ILLink : error IL1012: IL Trimmer has encountered an unexpected error. Please report the issue at https://aka.ms/report-illink [/Users/oploeger/Desktop/actions-runner/_work/Fitaino/Fitaino/apps/Fitaino.App/Fitaino.App.csproj::TargetFramework=net10.0-ios]
  Fatal error in IL Linker
  Unhandled exception. System.Collections.Generic.KeyNotFoundException: The given key 'Maui.Health.Services.HealthService/<GetHealthDataAsync>d__12`1' was not present in the dictionary.
     at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
     at Mono.Linker.Dataflow.CompilerGeneratedState.<GetCompilerGeneratedStateForType>g__MapGeneratedTypeTypeParameters|11_2(TypeDefinition generatedType, Dictionary`2 generatedTypeToTypeArgs, LinkContext context)
     at Mono.Linker.Dataflow.CompilerGeneratedState.<GetCompilerGeneratedStateForType>g__MapGeneratedTypeTypeParameters|11_2(TypeDefinition generatedType, Dictionary`2 generatedTypeToTypeArgs, LinkContext context)
     at Mono.Linker.Dataflow.CompilerGeneratedState.GetCompilerGeneratedStateForType(TypeDefinition type)
     at Mono.Linker.Dataflow.CompilerGeneratedState.GetGeneratedTypeAttributes(TypeDefinition generatedType)
     at ILLink.Shared.TrimAnalysis.FlowAnnotations.GetGeneratedTypeAttributes(TypeDefinition typeDef)
     at ILLink.Shared.TrimAnalysis.FlowAnnotations.BuildTypeAnnotations(TypeDefinition type)
     at ILLink.Shared.TrimAnalysis.FlowAnnotations.GetAnnotations(TypeDefinition type)
     at ILLink.Shared.TrimAnalysis.FlowAnnotations.GetTypeAnnotation(TypeDefinition type)
     at Mono.Linker.Dataflow.DynamicallyAccessedMembersTypeHierarchy.ProcessMarkedTypeForDynamicallyAccessedMembersHierarchy(TypeDefinition type)
     at Mono.Linker.Steps.MarkStep.MarkType(TypeReference reference, DependencyInfo reason, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.MarkTypeVisibleToReflection(TypeReference type, DependencyInfo& reason, MessageOrigin& origin)
     at Mono.Linker.Steps.MarkStep.MarkEntireType(TypeDefinition type, DependencyInfo& reason, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.MarkEntireType(TypeDefinition type, DependencyInfo& reason, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.MarkEntireAssembly(AssemblyDefinition assembly, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.MarkAssembly(AssemblyDefinition assembly, DependencyInfo reason, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.MarkModule(ModuleDefinition module, DependencyInfo reason, MessageOrigin origin)
     at Mono.Linker.Steps.MarkStep.ProcessMarkedPending()
     at Mono.Linker.Steps.MarkStep.Initialize()
     at Mono.Linker.Steps.MarkStep.Process(LinkContext context)
     at Mono.Linker.Pipeline.ProcessStep(LinkContext context, IStep step)
     at Mono.Linker.Pipeline.Process(LinkContext context)
     at Mono.Linker.Driver.Run(ILogger customLogger)
     at Mono.Linker.Driver.Main(String[] args)
/Users/oploeger/.nuget/packages/microsoft.net.illink.tasks/10.0.0/build/Microsoft.NET.ILLink.targets(103,5): error NETSDK1144: Optimizing assemblies for size failed. [/Users/oploeger/Desktop/actions-runner/_work/Fitaino/Fitaino/apps/Fitaino.App/Fitaino.App.csproj::TargetFramework=net10.0-ios]

Workaround:

I thought this workaround should work, but somehow I still get the same error

Exclude library from trimming in linker.xml:

<linker>
  <assembly fullname="Maui.Health" preserve="all" />
</linker>

.csproj

<ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios' OR $([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'android'">
	<TrimmerRootDescriptor Include="Linker.xml" />
</ItemGroup>

Thanks for this great Library
I am not sure how much work it would be to make this library trim/AOT ready, but I would love it ❤️

[Kebechet]

Hello @osyyyS
thank you for the feedback. I think this is a duplicate of #3

@Saurus119 is working on a new set of features in #6
and after they are done we will look into that. Because currently our main app doesnt use this new version so we didnt experience any issues (just debug builds)

So for sure we will look also into trimming.

[osyyyS]

@Kebechet thanks for the quick response, if I can help you with trimming, let me know!

I implemented the 2.0.0 in my app. It works great in debug and I am looking forward to shipping it 😄

[Kebechet]

@osyyyS thanks.

It could really help us if you could pinpoint the reason why the trimming is crippling the library. Or if possible also create a PR if some code-changes are needed.

The repo contains demo project so if needed you could test everything there for faster feedback loop.

[Kebechet]

Maybe related to:
dotnet/runtime#109821

I was trying to disable trimming and linking
<MtouchLink>None</MtouchLink>
<TrimmerRootAssembly Include="Maui.Health" RootMode="library"/>
on both library and app level but without success.

I also tried
<PublishTrimmed>false</PublishTrimmed> but Trimmer is required on iOS so I got an error iOS projects must build with PublishTrimmed=true. Current value: false. Set 'MtouchLink=None' instead to disable trimming for all assemblies.

Still researching.

[Kebechet]

Trimming problem was fixed with a workaround applied in:

• 469a1da
• d00d2fc

Fix available as: 2.0.0-preview14

And also reported to dotnet runtime repo:
dotnet/runtime#122800

[osyyyS]

@Kebechet Thank you so much 😊

[Kebechet]

Will keep this open till the linker issue is resolved and we will then remove the current workaround.